Statistical mechanics and molecular simulation of adsorption in microporous materials: Pillared clays and carbon molecular sieve membranes

We report the results of extensive equilibrium molecular dynamics simulation of adsorption of single-component and binary gas mixtures in models of two classes of microporous materials, namely, pillared clays and carbon molecular sieve membranes (CMSMs), both of which have been utilized for separation of gas mixtures. We develop a novel three-dimensional molecular pore network model for CMSMs based on Voronoi tessellation. The simulations allow us to investigate the effect of the morphology of the pore space, i.e., its pore size distribution and pore connectivity on the adsorption isotherms. The simulation results are also used to test the accuracy of a recently developed statistical mechanical theory of adsorption. The theory is shown to provide very accurate predictions for the simulation results for both classes of the microporous materials over a wide range of the porosity of the porous materials.